Integrate GoAdmin into main API with auto-migrations

- Admin panel accessible at /admin on the same domain
- GoAdmin tables created automatically during startup migrations
- Default credentials: admin / admin

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

cmd/api/main.go

@@ -9,9 +9,11 @@ import (
 	"syscall"
 	"time"
 
+	_ "github.com/lib/pq" // PostgreSQL driver for GoAdmin
 	"github.com/rs/zerolog/log"
 	"gorm.io/gorm"
 
+	"github.com/treytartt/mycrib-api/internal/admin"
 	"github.com/treytartt/mycrib-api/internal/config"
 	"github.com/treytartt/mycrib-api/internal/database"
 	"github.com/treytartt/mycrib-api/internal/router"
@@ -91,6 +93,15 @@ func main() {
 	}
 	r := router.SetupRouter(deps)
 
+	// Setup GoAdmin panel at /admin
+	if db != nil {
+		if _, err := admin.Setup(r, cfg); err != nil {
+			log.Warn().Err(err).Msg("Failed to setup admin panel - admin will be unavailable")
+		} else {
+			log.Info().Msg("Admin panel available at /admin")
+		}
+	}
+
 	// Create HTTP server
 	srv := &http.Server{
 		Addr:         fmt.Sprintf(":%d", cfg.Server.Port),